Drill bit gauge

ABSTRACT

The improved gauge of the invention incorporates both drill bit guide means and drill bit depth regulating means of an improved type. Neither the guide means nor the depth regulating means engages the drill bit so that work surface galling is prevented. The gauge further includes work surface contacting means, drill contacting means and may also include adjusting means engaging the work surface contacting means and drill contacting means.

I United States Patent 1191 1111 3,779,663 Ruggles Dec. 18, 1973 DRILL BIT GAUGE 3.119.285 1/1964 Steiner 408/14 x [76] Inventor: Clyde M. Ruggles, 6058 Fallbmok 3,537,336 11 /1970 Schmuck 408/72 Ave., Woodland Hills, Calif. Primary Examiner-Andrew R. Juhasz Flled: 1971 Assistant Examiner-Horace M. Culver [2]] Appl' No; 209,554 Attorney-John J. Posta, Jr.

52 US. Cl. 408/113 7] ABSTRACT [51] Int. Cl B23b /14, B23b 49/00 The impmved gauge of the invention incorporates Fleld of Search 72, both guide means and d p g 408/95 144/35 /11 33/18? 180 ing means of an improved type. Neither the guide 181 173/31 means nor the depth regulating means engages the drill bit so that work surface galling is prevented. The [56] References cued gauge further includes work surface contacting means, UNITED STATES PATENTS drill contacting means and may also include adjusting 1,929.585 l0/1933 Henry 408/l13 means engaging the work surface contacting means 2,675,003 4/1954 Veley..... 408/14 X and drill contacting means 2 978,93l 4/l96l Broden 408/113 X 2.997900 8/1961 Pugsley 408/ 4 Claims, 6 Drawing Figures \M- lZ 28 E r. T A I. '22 j 5 9 28 v 22 I O a l PATENTEDUEB m :97;

' INVENTOR. CLYDE RUGGLES 1 DRILL BIT GAUGE BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to the drill accessory art and more particularly to drill depth gauges.

2. Description of Prior Art The usual types of drill bit gauges are directly connected to the drill bit tip or shaft so that they rotate with the drill bit. As the drill bit drills into the work ,surface the gauge comes into contact with the work surface and, since the gauge is rotating with the bit, scoring or gallingof the work surface may occur. In order to avoid this happening, great care must be exercised in introducing the drill bit into the work surface to a depth just less than that which causes the gauge to strike the work surface. With such a procedure, variations in drilling depth frequently occur.

Drill bit guides most often employed are those in the form of templates or the like which overlie and obscure the work surface and which may impede the drilling operation. Accordingly it would be desirable to provide improved drill bit gauges and drill bit guides which would neither score the work surface nor obscure it from view during drilling.

SUMMARY OF THE INVENTION The present invention is substantially as is set forth in the abstract above. The improved drill bit depth gauge is adapted to both hand and electric drills of all sizes and types and is simple, durable, and inexpensive. It can be made adjustable and can be provided in a plurality of forms to suit specialized needs. In each such form the device is kept out of contact with the drill bit so that damage to the work surface, gauge and drill bit are avoided. Moreover, accurate positioning of the drill bit on the work surface is provided as well as predetermining the depth of the drilling to be carried out by the bit. Accordingly, uniform professional type drilling operations can be accomplished rapidly, as in countersinking or screw-hole drilling in relatively thin work surfaces where over-drilling may damage the product.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation of a first embodiment of the gauge of the invention, showing the gauge mounted on an electric drill.

FIG. 2 is a side elevation of a second embodiment of the gauge of the invention, with portions broken away to illustrate the relative positioning of the gauge and a drill bit before drilling begins.

FIG. 3 is a side elevation, partially broken away, of the device of FIG. 2 after drilling has been completed.

FIG. 4 is a side elevation of a third embodiment of the gauge of the invention.

FIG. 5 is a sectional view of the gauge of FIG. 4.

FIG. 6 is a perspective view of the gauge of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT A first embodiment of the improved gauge of the invention is illustrated in FIGS. 1 and 6. As shown in FIG. 6, an improved gauge 10 is provided which comprises drill bit guide means and depth regulating means. In this regard, device 10 includes an elongated element in the form of a threaded rod 12 positioned by a bracket assembly 14 generally parallel to but a predetermined distance from the counter-sinking drill bit I] of an electric drill 13. A work surface-contacting plate 16 with internally threaded upstanding collar ,18 is screwed on the lower end 20 of rod 12.

Bracket 14 includes a pair of curved wings 22, each containing a screw-receiving slot 24 in one end thereof and a rod-receiving aperture 34 in the other end thereof. Wings 22 are disposed in overlapping relation on rod 12 through apertures 26. Wings 22 are held in place on rod 12 by threaded nuts 28 positioned below and above overlapped wings 22. One transversely extending ear 30 of a vertically disposed bracket plate 32 (containing such an ear 30 at each end thereof) is dis posed between the upper nut 28 and upper wing 22, as shown in Figure 6. Each ear 30 contains an aperture 34 through which rod 12 is received. Plate 32 also defines a pair of vertically spaced apertures 36 adapted to receive housing screws 37 of electric drill 13, as shown particularly in Figure 1. It will be noted that wings 22 are adjustable, i.e., they pivot around their point of interconnection, so that they are adapted to fit electric drills of various shapes and sizes.

In order to fit bracket assembly 14 into electric drill 13, the drills housing screws 37 which align with apertures 36 are removed and are then inserted through apertures 36 and screwed tight. Housing screws 39 which fit into slots 24 are loosened enough to slip wings 22 between the screw shaft and head, and are then tightened. With the gauge screwed in place, as shown in FIG. 1, nuts 28 are loosened and rod 12 is adjusted vertically until the position of the bottom surface of plate 16 is a desired distance above the plane of the tip of the drill bit, as shown in FIG. 1. To hold rod 12 in the desired vertical location, nuts 28 are then tightened against lower wing 22 and lower car 30.

Drill 13 is now ready for use. Rod 12 and plate 16 are a fixed predetermined distance lateral of the centerline of the drill bit so that the drill bit can be more readily positioned by centering rod 12 and plate 16 over a suitable marked location on work surface 35. The drill is turned on and drilling down into the work surface 35 continues until the bottom surface of plate 16 abuts work surface 35. Accordingly, a simple, inexpensive device useful with drills for guiding and depth gauging purposes is provided. Device 10 can be fabricated of any suitable material, preferably steel for improved durability.

A second embodiment of the device of the invention is illustrated in FIGS. 2 and 3 in cross-section and side elevation (partly broken away), respectively. Thus, an improved gauge 40 is shown, which comprises a hollow generally cylindrical body 42 (which may be of another configuration, if desired) having a central aperture 44 extending therethrough. The upper end 46 of body 42 may be necked down, if desired, and is provided with a drill-contacting sleeve 48 with an upper, flat, peripherally extending surface 50. Sleeve 48 lines aperture 44 and preferably is fabricated of non-seizing, non-galling, friction-reducing material such as nylon, tetrafluoroethylene or the like. Sleeve 48 is dimensioned to loosely receive the shaft 59 of a drill bit 55, as illustrated in FIG. 2. The hollow interior 52 of body 42 is sufficiently large to accomodate the expanded counter sinking head or tip 53 of drill bit 55. The lower portion 54 of body 42 is open ended and flat so as to lie squarely on work surface 57.

Device 40 is utilized by passing shaft 59 of drill bit 55 up through aperture 44, then placing body 42 on work surface 57 so that tip 53 of drill bit 55 rests on that surface. Drill bit shaft 59 is then clamped in drill chuck 61 so that chuck 61 is a distance above surface 50 equal to the depth to which the tip 53 is to penetrate into work surface 57. When drilling is completed, bit head 53 is disposed in work surface 57, as shown, and chuck 61 contacts surface 50.

FIGS. 4 and illustrate in side elevation and crosssection, respectively, a third embodiment of the gauge of the present invention. In this regard, an improved gauge 70 is shown which includes a hollow cylindrical body 72 having an open bottom end 74 and a centrally aligned aperture 76 extending through the closed upper end 78 into communication with the hollow interior 80. Bottom end 74 is flat and serves to position body 72 squarely on a work surface 81. The wall defining aperture 76 is threaded and aperture 76 threadably receives a vertically aligned externally threaded shaft 82 fitted at the upper end 84 thereof with a drill-contacting plate 86 having a hollow collar 88 extending down therefrom and secured to shaft 82. The upper surface 90 of plate 86 may be provided, if desired, with a circular recess 92 in which may be secured, as shown in FIG. 5, a low friction chuck-contacting ring 94 fabricated of, for example, tetrofluoroethylene, nylon or the like. A pair of nuts 96 are threadably engaged with shaft 82 which shaft may also include a lower limit flange 98 or the like.

Shaft 82 and ring 94 have centrally aligned vertical apertures 100 and 102, respectively, dimensioned to receive the shaft 103 of a drill bit 105 bearing a tip or head 107. Bit 105 is connected to a chuck 109 of a drill (not shown) by passing shaft 82 up through open end 74 and aperture 100, then placing body 72 on work surface 81 so that tip 107 rests thereagainst. Shaft 103 of bit 105 is then clamped in chuck 109, after which the length of shaft 82 extending above end 78 of body 72 is regulated by loosening nuts 96, then turning shaft 82 via plate 86 in the appropriate direction to extend or retract it. Nuts 96 are then tightened against surface 90 and ring 94 and against each other. The distance between ring 94 and the lower end of chuck 109 determines the depth of drilling which can take place when the drill (not shown) is turned on and chuck 109 is moved down from the position shown in FIG. 4 to that shown in FIG. 5 so that it abuts ring 94. Accordingly, gauge 70 is fully and easily adjustable. Moreover, body 72 and shaft 82 act as an accurate drill guide. The hole to be drilled can first be marked and then the mark can be centered in aligned apertures and 102 with drill bit removed from body 72. A circle can then be drawn at the periphery of body 72 so that body 72 can be accurately repositioned for drilling when drill bit 105 is in place, as described above.

What is claimed and desired to be secured by Letters Patent is:

1. An improved drill bit gauge, which comprises, in combination,

a bracket assembly, and a depth regulating assembly, said depth regulating assembly including an elongated threaded element positioned a predetermined distance from and generally parallel to a drill bit, releasable adjusting means, and work-surface contacting means secured to one end of said elongated threaded element, said bracket assembly including a pair of curved wings, each of said wings defining a slot in one end thereof adapted to receive a first drill housing screw, each of said wings also having an aperture in the opposite end thereof adapted to receive and pivot about said elongated threaded element, said bracket assembly further including an elongated plate, said elongated plate further including a pair of transversely extending cars at each end thereof, said transversely extending ears defining elongated threaded element-receiving apertures, whereby said elongated threaded element is adapted to pass through the aperture in each of said wings and the aperture on each of said ears, and whereby said elongated element is maintained in a fixed, pre-determined position with respect to all of said apertures by said releasable adjusting means. 2. The improved drill bit gauge as set forth in claim 1 wherein said work-surface contacting means has an internally threaded, upstanding collar adapted to be screwed onto one end of said elongated threaded element.

3. The improved drill bit gauge as set forth in claim 2 wherein said releasable adjusting means comprises a plurality of threaded nuts.

4. The improved drill bit gauge as set forth in claim 3 wherein said elongated plate has a plurality of apertures extending along the length thereof adapted to receive a drill housing screw. 

1. An improved drill bit gauge, which comprises, in combination, a bracket assembly, and a depth regulating assembly, said depth regulating assembly including an elongated threaded element positioned a predetermined distance from and generally parallel to a drill bit, releasable adjusting means, and work-surface contacting means secured to one end of said elongated threaded element, said bracket assembly including a pair of curved wings, each of said wings defining a slot in one end thereof adapted to receive a first drill housing screw, each of said wings also having an aperture in the opposite end thereof adapted to receive and pivot about said elongated threaded element, said bracket assembly further including an elongated plate, said elongated plate further including a pair of transversely extending ears at each end thereof, said transversely extending ears defining elongated threaded element-receiving apertures, whereby said elongated threaded element is adapted to pass through the aperture in each of said wings and the aperture on each of said ears, and whereby said elongated element is maintained in a fixed, pre-determined position with respect to all of said apertures by said rEleasable adjusting means.
 2. The improved drill bit gauge as set forth in claim 1 wherein said work-surface contacting means has an internally threaded, upstanding collar adapted to be screwed onto one end of said elongated threaded element.
 3. The improved drill bit gauge as set forth in claim 2 wherein said releasable adjusting means comprises a plurality of threaded nuts.
 4. The improved drill bit gauge as set forth in claim 3 wherein said elongated plate has a plurality of apertures extending along the length thereof adapted to receive a drill housing screw. 